Device for transmitting sound-waves.



A. DARE.

DEVICE FOR TBANSMITTIHG SOUND WAVES.

APPLIGATION FILED FEB. 24, 1908.

Patented Dec. 22, 1908,

' adjusted to and from each other to facilitate time the sound waves set up in the larynx' ARTHUR DARE, OF PHILADELPHIA, PENNSYLVANIA.

DEVICE FOR TRANSMITTING SOUND-WAVES.

Specification of Letters Patent.

Patented. Dec. 22. 19.08.

Application filed February 24. 1908. Serial .No. 417,481.

To all whom it may concern:

Be it known that I, ARTHU DARE, a citizen of the United States, residing at ho. 1700 \Valnut street, Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful improvements in Devices for Transmitting Soundavas; and I do declare the follow ing to be a lull, clear, and exact description of the invention, such as will enable others skilled in the art to which it 'appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to improvements in devices for transmitting sound waves of the human voice and is ada ,ted for use in connect-ion with the telephone, phonograph and other like sound transmitting and recording instruments.

The invention -embodies device so constructed that when placed over the mouth the sound of speech will be muffled and rendered inaudible from without yet at the same will be permitted to travel to the diaphragm of the recording or traiiisinitting instrument released only from the pressure of exhaled air from the lungs. This is accomplished by the employment of a mouth piece of ample size having pressure exits communicating with an expansion chamber otsutticient capacity to reduce the pressure and permit the exhaled air to passout at a reduced pressure to the atmosphere. 7

A further object. of my invention is to absorb and prevent a reflex action of the diaphragm on the receiving side of the instrument by the employment of a double series of parallel non-resonant tubes which may be the intensity of sound in the transmission of long or short distance communications.

The nature of my invention will be best understood when viewed in connection with the accompanying drawings forming part of the specification and i1rwhich Figure 1 illustrates a side elevation of a telephone transmitter constructed in accordance with my invention. Fig. 2 shows ahorizontal section of the same as taken on a line indicated at 2-2 in Fig. 1. Fig. 3. is. a vertical section taken on a line 3-3 of 2.

Fig. 4 is a similar section taken at l -4 of Fig 2. Fig. 5 denotes a diagrammatic sec- 1 tion similar to Fig. 2 of a portion ofthe a paratus on a reduced scale showing-a slig tly moditied form of expansion. chamber and Fig. 6 shows a similardiagrammaticsection of the pipe leading to the diaphragm casing,

the pipe in this instance beingex-pande'd to form an expansion chamber-which is pr'o vided with discharge oriiices as. is the case with the form shown in l igs. 1 and 2;

teferring now to the letters indicating similar parts throughout the drawings, A, is the box or inclosure of a telephone containing the conventional diap ragm A and cori-. tact button A B, is the transmitter box comprising conical chambers B and B the former of which is provided with a mouth piece .13 which is detachably secured in place by set screws b, Z), etc. The conical chamber. B projects into the chamber 13 and is provided with a number ofannular pressure exits b, b, etc, which form oblique or, indirect lines of communication with thechamber B The chamber B is also provided with a flanged opening B*, for the reception of a compact mass of small tubes bfib etc. formed cl rubber or a like -nonrcsonant material. The chamber B" which is designed as an expansion chamber is provided with a number of annular openings or pressure exits 1), etc. through which exhalations of air are free to passto the atmosphere. Thereduced end of the'conical chamber B, loosely surrounds a pipe C, so that by operating a lever D, through its connecting link D, it will move the two chambers. of the transmitter box forward or backward upon. the pipe C. The pipe 0, is firmly secured to the box creasing A, containing the .dia bra-gm and its connections and said pipe 1s filled at its forward end with a number of small tubes 0 similarto the tubes btand made, of a like non-resonant material. The lever D, bywhi ch the transmitter-box or slidable member of the device is operated is fulcrumed to a bracket D by a pin Li and by the link D, is fulcrumed at a point (1 to a ring on the chamber B.

In using the instrument the operator places the mouth within the mouth piece B and in speaking the pressure due to the exhaled air from the lungs will be almost entirely eliminated by the free exit afforded by the openings 6 and b permitting the more delicate sound waves of s eech to pass through the non-resonant an parallel masses of tubes 12 and c to the diaphragm A.

During a course of experimentation l. have found that good results may be obtained by constructing the expansion chamber in the manner shown in Fig. 5 in which case the inclosing wall 33 of the chamber is cylindrical as distinguished from the conical wall shown in the preferred form illustrated in Figs. 1 and 2. The pressure exits 12*, are here also modified being located between the chambers B and B and not within the inclosing wall of said chamber, as is the case with the preferred form.

A further modification of my invention is illustrated in Fig. 6 in which case the expansion chamber proper of the preferred form is eliminated and the tube C thereof is expanded as shown at O to act in lieu of an expansion chamber and as shown is provided with a number of discharge openings 0, e etc. H

It will be noted in Fig. 6 that a single system of tubes 0 is employed and that the surrounding casing or main tubeis devoid of a mouth piece it being preferred for sanitary reasons that the hand of the operator be used and interposed between the mouth and the tube in s eaking. In order to accomplish the resu ts with this single tube system as I have been able to accomplish by the double system of Figs. 1 and '2 t. e. the elimination of pressure other than that caused by speech, it is necessary that the tubes 0 etc. should be bent at an angle as shown at 0 which it has been found by experiment will to a very appreciableextent tend to dissipate the pressure due to the exhalation of air from the lungs which upon being detlected is released through the openings 0.

Having described my invention what 1 claim and desire to secure by Letters Patent is:

1. A telephone transmitter comprising two connected compartments one of which is fashioned to form a mouth piece and the other adapted to act as an expansion chamher, a series of non-resonant tubes arranged between the compartments, a pipe leading from the expansion chamber to the inclosure containing the diaphragm and a series of nonresonant tubes located within said pipe.

2. A telephone transmitter comprising eon-sac two compartments, the first of which is pro vided with side openings leading into the second compartment and the latter having side openings communicating with the atmosphere, a series of non-resonant tubes arranged between the compartments, a pipe leading from the second compartment to an inclosure containing the diaphragm and a second series of non-resonant tubes contained in said pipe.

3. A telephone transmitter comprising two connected conical chambers, a series of non-resonant tubes arranged between the climbers, a pipe leading from one of the chambers to an inclosure containing the diaphragm and its mechanism, and a series of non-reson ant tubes arranged within said pipe.

4. A telephone transmitter comprising two connected chambers provided with annular pressure exits, a series of non-resonant tubes interposedrbetween said chambers, a pipe leading from one of the chambers to the inclosure containing the diaphragm, a series of non-resonant tubes contained in said pipe and means whereby the distance between the two series of non-resonant tubes may be in creased or diminished.

5. A telephone transmitter comprising two connected conical chambers, the first of which is adapted to act as a mouth piece and the second as an expansion chamber, the first chamber being provided with annular open ings communicating with the second chamber and the latter having similar openings forming communications from without, a series of non-resonant tubes interposed between the Cl181111b61S, it pipe leading from the second chamber to a box containing the diaphragm and its mechanism, a series of non-resonant tubes contained within said pipe and means including a lever and connecting link for moving the chambers and consequently varymg the distance between the non-resonant tubes.

In testimony whereof I aihx my signature, in presence of two witnesses.

, ARTHUR DARE.

lVitnesses JAY R. Gnrnn, CHAS. C. COLLIER. 

